In the title compound, 3β-(dimethylamino)-16α-hydroxy-14-methyl-4-methylene-9,19-cyclo-5α-pregnan-20-one monohydrate, C
25H
39NO
2·H
2O, the pentacyclo steroidal alkaloid is composed of three six-membered, one five-membered and one three-membered ring. The molecular dimensions are as expected. The structure is stabilized by hydrogen bonds involving H and O atoms of water and the alkaloid molecules, with strong N
O [2.829 (7) Å] and O
O [2.790 (6) and 2.949 (7) Å] interactions.
Supporting information
CCDC reference: 142770
The leaves of Buxus hyrcana were collected from Tehran, Iran, during March and April, 1997. The methanolic extract of the air-dried and crushed leaves was evaporated to a gum, which was then suspended in water. After defatting with hexane, the aqueous layer was extracted with chloroform at different pH values. The fraction obtained at pH 3 was subjected to column chromatography. Elution of the column with chloroform:methanol (9:1) afforded the crystals of (I). Crystals suitable for X-ray crystallography were grown from acetone:methanol (9:1) at room temperature by slow evaporation.
The space group P21 was determined from the systematic absences, packing considerations, a statistical analysis of intensity distribution, and the successful solution and refinement of the structure. Friedel opposites (2689) were collected and were not merged. H-atoms of the water of solvation and hydroxyl group were located from a difference map. H atoms of the alkaloid were included at riding positions. The water H atoms were left in fixed positions. An absolute configuration could not be established in this analysis. However, refinement of the inverted structure towards the end of the full-matrix least-squares calculations yielded a Flack (1983) parameter of 2(3) and was, therefore, rejected as the absolute structure present in the crystal.
Data collection: MSC/AFC Diffractometer Control Software
(Molecular Structure Corporation, 1988); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1994); program(s) used to solve structure: SAPI91 (Fan, 1991); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).
3
β-(Dimethylamino)-16
α-hydroxy-14-methyl-4-methylene-9,19-
cyclo-5
α- pregnan-20-one monohydrate
top
Crystal data top
C25H39NO2·H2O | F(000) = 444 |
Mr = 403.59 | Dx = 1.172 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71069 Å |
a = 6.1333 (8) Å | Cell parameters from 25 reflections |
b = 24.365 (3) Å | θ = 10.0–25.0° |
c = 8.0681 (6) Å | µ = 0.08 mm−1 |
β = 108.496 (8)° | T = 293 K |
V = 1143.4 (2) Å3 | Prismatic, colourless |
Z = 2 | 0.38 × 0.29 × 0.25 mm |
Data collection top
Rigaku AFC-6S diffractometer | 2901 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.038 |
Graphite monochromator | θmax = 27.6°, θmin = 2.7° |
ω–2θ scans | h = 0→7 |
Absorption correction: ψ scan (North, Phillips & Mathews, 1968) | k = −31→31 |
Tmin = 0.972, Tmax = 0.981 | l = −10→9 |
5848 measured reflections | 3 standard reflections every 200 reflections |
5257 independent reflections | intensity decay: 0.1% |
Refinement top
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H atoms not refined |
R[F2 > 2σ(F2)] = 0.059 | w = 1/[σ2(Fo2) + (0.1023P)2 + 1.323P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.255 | (Δ/σ)max = 0.002 |
S = 1.07 | Δρmax = 0.22 e Å−3 |
5257 reflections | Δρmin = −0.24 e Å−3 |
270 parameters | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
1 restraint | Extinction coefficient: 0.009 (4) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983) |
Secondary atom site location: difference Fourier map | Absolute structure parameter: −1 (3) |
Crystal data top
C25H39NO2·H2O | V = 1143.4 (2) Å3 |
Mr = 403.59 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 6.1333 (8) Å | µ = 0.08 mm−1 |
b = 24.365 (3) Å | T = 293 K |
c = 8.0681 (6) Å | 0.38 × 0.29 × 0.25 mm |
β = 108.496 (8)° | |
Data collection top
Rigaku AFC-6S diffractometer | 2901 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North, Phillips & Mathews, 1968) | Rint = 0.038 |
Tmin = 0.972, Tmax = 0.981 | 3 standard reflections every 200 reflections |
5848 measured reflections | intensity decay: 0.1% |
5257 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.059 | H atoms not refined |
wR(F2) = 0.255 | Δρmax = 0.22 e Å−3 |
S = 1.07 | Δρmin = −0.24 e Å−3 |
5257 reflections | Absolute structure: Flack (1983) |
270 parameters | Absolute structure parameter: −1 (3) |
1 restraint | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.9274 (8) | −0.08845 (19) | 0.9604 (6) | 0.0750 (15) | |
H1 | 1.0012 | −0.0607 | 0.9569 | 0.113* | |
O2 | 0.5150 (9) | 0.02603 (19) | 0.7301 (7) | 0.0743 (13) | |
N1 | −0.0547 (9) | −0.39785 (19) | −0.0391 (6) | 0.0494 (12) | |
C1 | 0.3067 (10) | −0.2637 (2) | 0.0788 (7) | 0.0483 (13) | |
H1A | 0.3051 | −0.2303 | 0.0131 | 0.058* | |
H1B | 0.4592 | −0.2797 | 0.1084 | 0.058* | |
C2 | 0.1301 (12) | −0.3039 (2) | −0.0320 (7) | 0.0553 (15) | |
H2A | 0.1726 | −0.3137 | −0.1342 | 0.066* | |
H2B | −0.0186 | −0.2860 | −0.0720 | 0.066* | |
C3 | 0.1091 (10) | −0.3568 (2) | 0.0671 (7) | 0.0428 (12) | |
H3 | 0.2610 | −0.3742 | 0.1016 | 0.051* | |
C4 | 0.0631 (9) | −0.3416 (2) | 0.2352 (6) | 0.0386 (11) | |
C5 | 0.2451 (8) | −0.30313 (19) | 0.3467 (6) | 0.0344 (10) | |
H5 | 0.3923 | −0.3214 | 0.3609 | 0.041* | |
C6 | 0.2396 (10) | −0.2928 (2) | 0.5323 (6) | 0.0419 (12) | |
H6A | 0.0919 | −0.2775 | 0.5281 | 0.050* | |
H6B | 0.2608 | −0.3271 | 0.5965 | 0.050* | |
C7 | 0.4298 (9) | −0.2530 (2) | 0.6234 (6) | 0.0423 (12) | |
H7A | 0.5744 | −0.2662 | 0.6134 | 0.051* | |
H7B | 0.4445 | −0.2512 | 0.7465 | 0.051* | |
C8 | 0.3798 (8) | −0.19572 (19) | 0.5433 (6) | 0.0328 (10) | |
H8 | 0.2389 | −0.1832 | 0.5642 | 0.039* | |
C9 | 0.3270 (8) | −0.1963 (2) | 0.3415 (6) | 0.0349 (10) | |
C10 | 0.2510 (8) | −0.2504 (2) | 0.2454 (6) | 0.0362 (10) | |
C11 | 0.4589 (9) | −0.1557 (2) | 0.2610 (6) | 0.0434 (12) | |
H11A | 0.5897 | −0.1752 | 0.2466 | 0.052* | |
H11B | 0.3589 | −0.1464 | 0.1449 | 0.052* | |
C12 | 0.5485 (9) | −0.1018 (2) | 0.3571 (6) | 0.0438 (12) | |
H12A | 0.7119 | −0.0988 | 0.3744 | 0.053* | |
H12B | 0.4726 | −0.0713 | 0.2844 | 0.053* | |
C13 | 0.5086 (8) | −0.09750 (18) | 0.5351 (6) | 0.0334 (10) | |
C14 | 0.5673 (8) | −0.15371 (18) | 0.6329 (6) | 0.0326 (10) | |
C15 | 0.5748 (10) | −0.1375 (2) | 0.8192 (6) | 0.0426 (12) | |
H15A | 0.4206 | −0.1350 | 0.8272 | 0.051* | |
H15B | 0.6612 | −0.1643 | 0.9036 | 0.051* | |
C16 | 0.6941 (9) | −0.0812 (2) | 0.8527 (7) | 0.0470 (12) | |
H16 | 0.6139 | −0.0568 | 0.9107 | 0.056* | |
C17 | 0.6778 (9) | −0.0581 (2) | 0.6702 (7) | 0.0412 (12) | |
H17 | 0.8296 | −0.0624 | 0.6558 | 0.049* | |
C18 | 0.2601 (9) | −0.0792 (2) | 0.5063 (7) | 0.0491 (13) | |
H18A | 0.2367 | −0.0434 | 0.4542 | 0.074* | |
H18B | 0.2316 | −0.0780 | 0.6166 | 0.074* | |
H18C | 0.1564 | −0.1048 | 0.4303 | 0.074* | |
C19 | 0.0762 (8) | −0.2070 (2) | 0.2362 (6) | 0.0398 (11) | |
H19A | −0.0312 | −0.2131 | 0.3004 | 0.048* | |
H19B | 0.0130 | −0.1876 | 0.1265 | 0.048* | |
C20 | 0.6165 (10) | 0.0024 (2) | 0.6466 (7) | 0.0489 (13) | |
C21 | 0.6887 (14) | 0.0311 (3) | 0.5068 (9) | 0.075 (2) | |
H21A | 0.6477 | 0.0692 | 0.5034 | 0.113* | |
H21B | 0.6123 | 0.0145 | 0.3955 | 0.113* | |
H21C | 0.8520 | 0.0278 | 0.5326 | 0.113* | |
C22 | −0.1114 (10) | −0.3597 (2) | 0.2815 (8) | 0.0513 (13) | |
H22A | −0.1276 | −0.3490 | 0.3876 | 0.062* | |
H22B | −0.2185 | −0.3833 | 0.2081 | 0.062* | |
C23 | 0.8070 (9) | −0.1740 (2) | 0.6385 (7) | 0.0450 (12) | |
H23A | 0.8514 | −0.2043 | 0.7181 | 0.067* | |
H23B | 0.9162 | −0.1447 | 0.6772 | 0.067* | |
H23C | 0.8029 | −0.1856 | 0.5238 | 0.067* | |
C24 | −0.2753 (12) | −0.3756 (3) | −0.1430 (9) | 0.073 (2) | |
H24A | −0.3226 | −0.3478 | −0.0771 | 0.109* | |
H24B | −0.3877 | −0.4044 | −0.1725 | 0.109* | |
H24C | −0.2615 | −0.3597 | −0.2481 | 0.109* | |
C25 | 0.0499 (14) | −0.4287 (3) | −0.1517 (9) | 0.0691 (19) | |
H25A | −0.0604 | −0.4541 | −0.2225 | 0.104* | |
H25B | 0.1815 | −0.4485 | −0.0802 | 0.104* | |
H25C | 0.0966 | −0.4036 | −0.2257 | 0.104* | |
O3 | 0.1742 (9) | 0.00264 (19) | 0.9091 (8) | 0.0832 (16) | |
H31 | 0.2863 | 0.0024 | 0.8749 | 0.094* | |
H32 | 0.1539 | 0.0350 | 0.9280 | 0.094* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.072 (3) | 0.057 (3) | 0.068 (3) | −0.021 (2) | −0.018 (2) | 0.018 (2) |
O2 | 0.087 (3) | 0.045 (2) | 0.097 (4) | 0.009 (2) | 0.039 (3) | −0.007 (2) |
N1 | 0.061 (3) | 0.045 (3) | 0.040 (2) | −0.001 (2) | 0.013 (2) | −0.0032 (19) |
C1 | 0.068 (4) | 0.044 (3) | 0.040 (3) | −0.008 (3) | 0.028 (3) | −0.003 (2) |
C2 | 0.082 (4) | 0.053 (4) | 0.033 (3) | −0.010 (3) | 0.020 (3) | −0.001 (2) |
C3 | 0.054 (3) | 0.038 (3) | 0.038 (3) | 0.002 (2) | 0.016 (2) | −0.002 (2) |
C4 | 0.043 (3) | 0.036 (3) | 0.038 (3) | 0.001 (2) | 0.014 (2) | 0.002 (2) |
C5 | 0.040 (3) | 0.035 (2) | 0.032 (2) | 0.006 (2) | 0.016 (2) | 0.000 (2) |
C6 | 0.056 (3) | 0.041 (3) | 0.033 (2) | −0.003 (2) | 0.020 (2) | 0.005 (2) |
C7 | 0.056 (3) | 0.044 (3) | 0.027 (2) | −0.002 (2) | 0.014 (2) | 0.006 (2) |
C8 | 0.035 (2) | 0.036 (2) | 0.032 (2) | 0.004 (2) | 0.0157 (19) | 0.0036 (18) |
C9 | 0.036 (2) | 0.039 (3) | 0.031 (2) | 0.005 (2) | 0.0120 (19) | 0.006 (2) |
C10 | 0.042 (3) | 0.040 (3) | 0.028 (2) | 0.001 (2) | 0.0140 (19) | 0.0023 (19) |
C11 | 0.050 (3) | 0.049 (3) | 0.034 (2) | 0.005 (2) | 0.018 (2) | 0.009 (2) |
C12 | 0.050 (3) | 0.043 (3) | 0.040 (3) | −0.007 (2) | 0.016 (2) | 0.006 (2) |
C13 | 0.034 (2) | 0.031 (2) | 0.038 (2) | 0.002 (2) | 0.014 (2) | 0.004 (2) |
C14 | 0.036 (3) | 0.029 (2) | 0.035 (2) | 0.002 (2) | 0.0137 (19) | 0.0070 (18) |
C15 | 0.050 (3) | 0.043 (3) | 0.036 (2) | 0.006 (2) | 0.014 (2) | 0.001 (2) |
C16 | 0.054 (3) | 0.041 (3) | 0.042 (3) | 0.004 (2) | 0.009 (2) | 0.005 (2) |
C17 | 0.043 (3) | 0.038 (3) | 0.042 (3) | −0.002 (2) | 0.012 (2) | 0.004 (2) |
C18 | 0.040 (3) | 0.044 (3) | 0.060 (3) | 0.006 (2) | 0.012 (2) | 0.005 (3) |
C19 | 0.041 (3) | 0.035 (3) | 0.040 (3) | 0.003 (2) | 0.007 (2) | 0.005 (2) |
C20 | 0.054 (3) | 0.032 (3) | 0.053 (3) | 0.003 (2) | 0.007 (3) | 0.000 (2) |
C21 | 0.109 (6) | 0.046 (4) | 0.065 (4) | −0.014 (4) | 0.019 (4) | 0.011 (3) |
C22 | 0.058 (3) | 0.049 (3) | 0.052 (3) | −0.009 (3) | 0.024 (3) | −0.006 (3) |
C23 | 0.040 (3) | 0.042 (3) | 0.053 (3) | 0.008 (2) | 0.015 (2) | 0.006 (2) |
C24 | 0.072 (5) | 0.071 (5) | 0.058 (4) | 0.002 (4) | −0.004 (3) | −0.003 (3) |
C25 | 0.100 (6) | 0.051 (4) | 0.062 (4) | −0.006 (4) | 0.033 (4) | −0.011 (3) |
O3 | 0.094 (4) | 0.045 (3) | 0.129 (4) | −0.007 (2) | 0.061 (3) | −0.013 (3) |
Geometric parameters (Å, º) top
O1—C16 | 1.430 (6) | C8—C9 | 1.556 (6) |
O2—C20 | 1.200 (7) | C9—C10 | 1.525 (7) |
N1—C24 | 1.452 (8) | C9—C19 | 1.526 (7) |
N1—C25 | 1.473 (8) | C9—C11 | 1.545 (7) |
N1—C3 | 1.482 (7) | C10—C19 | 1.490 (7) |
C1—C2 | 1.522 (8) | C11—C12 | 1.536 (7) |
C1—C10 | 1.523 (7) | C12—C13 | 1.535 (6) |
C2—C3 | 1.543 (7) | C13—C18 | 1.533 (7) |
C3—C4 | 1.517 (7) | C13—C14 | 1.565 (6) |
C4—C22 | 1.317 (7) | C13—C17 | 1.572 (7) |
C4—C5 | 1.515 (7) | C14—C23 | 1.538 (7) |
C5—C6 | 1.529 (6) | C14—C15 | 1.541 (7) |
C5—C10 | 1.530 (6) | C15—C16 | 1.539 (8) |
C6—C7 | 1.514 (7) | C16—C17 | 1.550 (7) |
C7—C8 | 1.528 (7) | C17—C20 | 1.517 (7) |
C8—C14 | 1.538 (7) | C20—C21 | 1.507 (9) |
| | | |
C24—N1—C25 | 110.0 (5) | C19—C10—C5 | 118.9 (4) |
C24—N1—C3 | 114.7 (5) | C1—C10—C5 | 110.0 (4) |
C25—N1—C3 | 110.6 (5) | C9—C10—C5 | 120.6 (4) |
C2—C1—C10 | 109.8 (5) | C12—C11—C9 | 119.1 (4) |
C1—C2—C3 | 113.2 (4) | C13—C12—C11 | 113.1 (4) |
N1—C3—C4 | 113.4 (4) | C18—C13—C12 | 108.9 (4) |
N1—C3—C2 | 114.6 (4) | C18—C13—C14 | 112.9 (4) |
C4—C3—C2 | 109.2 (4) | C12—C13—C14 | 109.4 (4) |
C22—C4—C5 | 123.4 (5) | C18—C13—C17 | 109.5 (4) |
C22—C4—C3 | 124.7 (5) | C12—C13—C17 | 115.1 (4) |
C5—C4—C3 | 111.8 (4) | C14—C13—C17 | 100.9 (4) |
C4—C5—C6 | 116.3 (4) | C8—C14—C23 | 111.4 (4) |
C4—C5—C10 | 109.9 (4) | C8—C14—C15 | 114.6 (4) |
C6—C5—C10 | 113.3 (4) | C23—C14—C15 | 108.7 (4) |
C7—C6—C5 | 109.2 (4) | C8—C14—C13 | 109.1 (4) |
C6—C7—C8 | 111.0 (4) | C23—C14—C13 | 111.2 (4) |
C7—C8—C14 | 112.9 (4) | C15—C14—C13 | 101.5 (4) |
C7—C8—C9 | 112.4 (4) | C16—C15—C14 | 105.4 (4) |
C14—C8—C9 | 112.0 (4) | O1—C16—C15 | 108.9 (4) |
C10—C9—C19 | 58.5 (3) | O1—C16—C17 | 111.9 (5) |
C10—C9—C11 | 117.1 (4) | C15—C16—C17 | 105.9 (4) |
C19—C9—C11 | 116.5 (4) | C20—C17—C16 | 114.2 (5) |
C10—C9—C8 | 117.9 (4) | C20—C17—C13 | 115.1 (4) |
C19—C9—C8 | 115.0 (4) | C16—C17—C13 | 105.5 (4) |
C11—C9—C8 | 118.1 (4) | C10—C19—C9 | 60.8 (3) |
C19—C10—C1 | 117.8 (4) | O2—C20—C21 | 121.7 (6) |
C19—C10—C9 | 60.8 (3) | O2—C20—C17 | 123.2 (5) |
C1—C10—C9 | 121.0 (4) | C21—C20—C17 | 115.1 (5) |
| | | |
C10—C1—C2—C3 | −55.4 (7) | C19—C9—C11—C12 | 116.4 (5) |
C24—N1—C3—C4 | 80.0 (6) | C8—C9—C11—C12 | −26.9 (6) |
C25—N1—C3—C4 | −154.8 (5) | C9—C11—C12—C13 | 4.6 (7) |
C24—N1—C3—C2 | −46.4 (7) | C11—C12—C13—C18 | −81.1 (5) |
C25—N1—C3—C2 | 78.8 (6) | C11—C12—C13—C14 | 42.7 (5) |
C1—C2—C3—N1 | −177.7 (5) | C11—C12—C13—C17 | 155.6 (4) |
C1—C2—C3—C4 | 53.8 (7) | C7—C8—C14—C23 | 53.5 (5) |
N1—C3—C4—C22 | −3.8 (8) | C9—C8—C14—C23 | −74.6 (5) |
C2—C3—C4—C22 | 125.4 (6) | C7—C8—C14—C15 | −70.5 (5) |
N1—C3—C4—C5 | 175.4 (4) | C9—C8—C14—C15 | 161.4 (4) |
C2—C3—C4—C5 | −55.4 (6) | C7—C8—C14—C13 | 176.6 (4) |
C22—C4—C5—C6 | 9.3 (7) | C9—C8—C14—C13 | 48.5 (5) |
C3—C4—C5—C6 | −170.0 (4) | C18—C13—C14—C8 | 49.6 (5) |
C22—C4—C5—C10 | −121.1 (5) | C12—C13—C14—C8 | −71.9 (5) |
C3—C4—C5—C10 | 59.6 (5) | C17—C13—C14—C8 | 166.3 (4) |
C4—C5—C6—C7 | −179.2 (4) | C18—C13—C14—C23 | 172.9 (4) |
C10—C5—C6—C7 | −50.4 (6) | C12—C13—C14—C23 | 51.4 (5) |
C5—C6—C7—C8 | 69.0 (5) | C17—C13—C14—C23 | −70.4 (5) |
C6—C7—C8—C14 | 179.4 (4) | C18—C13—C14—C15 | −71.7 (5) |
C6—C7—C8—C9 | −52.7 (5) | C12—C13—C14—C15 | 166.8 (4) |
C7—C8—C9—C10 | 20.5 (6) | C17—C13—C14—C15 | 45.0 (4) |
C14—C8—C9—C10 | 148.8 (4) | C8—C14—C15—C16 | −157.3 (4) |
C7—C8—C9—C19 | 86.5 (5) | C23—C14—C15—C16 | 77.3 (5) |
C14—C8—C9—C19 | −145.1 (4) | C13—C14—C15—C16 | −39.9 (5) |
C7—C8—C9—C11 | −129.7 (4) | C14—C15—C16—O1 | −102.0 (5) |
C14—C8—C9—C11 | −1.3 (6) | C14—C15—C16—C17 | 18.5 (5) |
C2—C1—C10—C19 | −83.2 (6) | O1—C16—C17—C20 | −103.9 (5) |
C2—C1—C10—C9 | −154.2 (5) | C15—C16—C17—C20 | 137.5 (5) |
C2—C1—C10—C5 | 57.4 (6) | O1—C16—C17—C13 | 128.7 (5) |
C11—C9—C10—C19 | −105.9 (5) | C15—C16—C17—C13 | 10.2 (5) |
C8—C9—C10—C19 | 103.6 (4) | C18—C13—C17—C20 | −41.8 (6) |
C19—C9—C10—C1 | 106.7 (5) | C12—C13—C17—C20 | 81.3 (6) |
C11—C9—C10—C1 | 0.8 (7) | C14—C13—C17—C20 | −161.0 (4) |
C8—C9—C10—C1 | −149.6 (4) | C18—C13—C17—C16 | 85.1 (5) |
C19—C9—C10—C5 | −108.2 (5) | C12—C13—C17—C16 | −151.9 (4) |
C11—C9—C10—C5 | 145.9 (4) | C14—C13—C17—C16 | −34.2 (5) |
C8—C9—C10—C5 | −4.5 (6) | C1—C10—C19—C9 | −111.9 (5) |
C4—C5—C10—C19 | 80.3 (5) | C5—C10—C19—C9 | 111.0 (4) |
C6—C5—C10—C19 | −51.7 (6) | C11—C9—C19—C10 | 106.9 (4) |
C4—C5—C10—C1 | −59.9 (5) | C8—C9—C19—C10 | −108.7 (4) |
C6—C5—C10—C1 | 168.1 (4) | C16—C17—C20—O2 | −24.3 (8) |
C4—C5—C10—C9 | 151.6 (4) | C13—C17—C20—O2 | 97.9 (6) |
C6—C5—C10—C9 | 19.6 (6) | C16—C17—C20—C21 | 156.8 (5) |
C10—C9—C11—C12 | −177.3 (4) | C13—C17—C20—C21 | −80.9 (6) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H31···O2 | 0.82 | 2.17 | 2.949 (7) | 159.4 |
O3—H32···N1i | 0.82 | 2.05 | 2.829 (7) | 158.9 |
O1—H1···O3ii | 0.82 | 1.98 | 2.790 (6) | 171 |
Symmetry codes: (i) −x, y+1/2, −z+1; (ii) x+1, y, z. |
Experimental details
Crystal data |
Chemical formula | C25H39NO2·H2O |
Mr | 403.59 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 293 |
a, b, c (Å) | 6.1333 (8), 24.365 (3), 8.0681 (6) |
β (°) | 108.496 (8) |
V (Å3) | 1143.4 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.38 × 0.29 × 0.25 |
|
Data collection |
Diffractometer | Rigaku AFC-6S diffractometer |
Absorption correction | ψ scan (North, Phillips & Mathews, 1968) |
Tmin, Tmax | 0.972, 0.981 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5848, 5257, 2901 |
Rint | 0.038 |
(sin θ/λ)max (Å−1) | 0.651 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.059, 0.255, 1.07 |
No. of reflections | 5257 |
No. of parameters | 270 |
No. of restraints | 1 |
H-atom treatment | H atoms not refined |
Δρmax, Δρmin (e Å−3) | 0.22, −0.24 |
Absolute structure | Flack (1983) |
Absolute structure parameter | −1 (3) |
Selected geometric parameters (Å, º) topO1—C16 | 1.430 (6) | C4—C22 | 1.317 (7) |
O2—C20 | 1.200 (7) | C9—C10 | 1.525 (7) |
N1—C24 | 1.452 (8) | C9—C19 | 1.526 (7) |
N1—C25 | 1.473 (8) | C10—C19 | 1.490 (7) |
N1—C3 | 1.482 (7) | | |
| | | |
C24—N1—C25 | 110.0 (5) | C10—C9—C19 | 58.5 (3) |
C24—N1—C3 | 114.7 (5) | C19—C10—C9 | 60.8 (3) |
C25—N1—C3 | 110.6 (5) | C10—C19—C9 | 60.8 (3) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H31···O2 | 0.82 | 2.17 | 2.949 (7) | 159.4 |
O3—H32···N1i | 0.82 | 2.05 | 2.829 (7) | 158.9 |
O1—H1···O3ii | 0.82 | 1.98 | 2.790 (6) | 170.6 |
Symmetry codes: (i) −x, y+1/2, −z+1; (ii) x+1, y, z. |
Buxus species have long been known as rich sources of new and biologically active triterpenoidal alkaloids. Previous phytochemical investigations have led to the isolation of 150 such compounds (Atta-ur-Rahman, 1990). The extracts of the genus Buxus are reported to be useful in the indigenous system of medicine, in various disorders such as malaria, rheumatism and skin infections (Cordell, 1980). In this article, we report the crystal structure of the title compound (I), an interesting steroidal alkaloid isolated from the leaves of B. hyrcana, collected from Tehran, Iran.
The crystal structure of (I) is presented in Fig. 1. It contains a pentacyclo steroidal alkaloid hydrogen bonded to a water molecule. The molecular dimensions in (I) are normal and lie within expected ranges for the corresponding bond distances and angles, with mean bond distances as follows: Csp3—Csp3 1.535 (7), Csp3—Csp2 1.514 (4), N—Csp3 1.469 (10), C—O 1.430 (6), C═O 1.200 (7) and C═C 1.317 (7) Å. The alkaloid is composed of three six-membered, one five-membered and one three-membered ring. The six-membered rings A, B and C adopt chair, half-chair and skew-boat conformations, respectively, with puckering parameters (Cremer & Pople, 1975) Q = 0.586 (6), 0.530 (6) and 0.638 (5) Å, θ = 3.9 (6), 47.1 (5) and 68.9 (4)° and ϕ = 263 (9), 91.2 (8) and 273.9 (5)°, respectively. The five-membered ring D has a C14-envelope conformation with C14 0.675 (7) Å out of the plane of the remaining four atoms of the ring.
The structure is stabilized by hydrogen bonds involving the alkaloid molecules and water of hydration, with strong N···O [2.829 (7) Å] and O···O [2.790 (6) and 2.949 (7) Å] interactions. The geometry of the intermolecular interactions is provided in Table 2.